1. Field of the Invention
This invention generally relates to emergency alarm sensors and, more particularly, to a system and method for detecting water leakage in a building structure.
2. Description of the Related Art
Plumbing failures in residential and commercial building result in millions of dollars of damage each year, in this country alone. As a result, systems have been designed to detect pools of water or leakage from a pipe. For example, conductive liquid sensors are known that consist of two electrically conductive materials formed on an insulating material in close proximity, but without touching. When liquid is sensed across the two conductive materials, the resistance between the conductive materials drops. This reduction in resistance is monitored, and a decrease in resistance can indicate the presence of liquid. This method provides an economical means to sense liquid on floor surfaces due to leaks in pipes, failed fittings, leaking valves, and floods.
One reference describes sensors that may be joined in “L” or “T” shaped combinations, see U.S. Pat. No. 4,297,686, invented by M. Dale Tom. The sensors may be connected in various configurations to provide a wider coverage area. The sensors are connected to a detection circuit that measures resistance. However, these sensors do not allow for the simple connection of different sensor types. Nor can these sensors to be connected together remotely, in multiple locations. That is, these sensors cannot be configured into centralized network that performs an overall water monitoring function for an entire building.
Further, these sensors are essentially two-dimensional. They can be located over a wall or a floor, for example. While these sensors may be sufficient to detect flooding and pools of water, they cannot necessarily detect water build-up in materials such as drywall or carpeting. As a result, an alarm may not be sounded until significant damage has been done.
It would be advantageous if a centralized system could be provided to monitor water in a plurality of locations throughout a building.
It would be advantageous if a water, or liquid detection sensor could be provided that was able to detect water in a building material such as drywall or carpeting.
It would be advantageous if liquid detection sensors could be integrally formed in building materials such as plywood, drywall, and insulation.
It would be advantageous if the above-mentioned integrally formed sensors could be networked to form a building-wide liquid detection system.